Referring to FIG. 1, the heart 2 includes a mitral valve 6 that has a valve annulus 4. As a result of age, congenital defect or disease, the mitral valve 6 may fail to close completely when it should during a heartbeat. The normal mitral valve 6 opens when the left ventricle 8 relaxes (diastole), allowing blood from the left atrium 10 to fill the decompressed left ventricle 8. When the left ventricle 8 contracts (systole), the increase in pressure within the left ventricle 8 causes the mitral valve 6 to close, preventing blood from leaking into the left atrium 10 and assuring that all of the blood leaving the left ventricle 8 (the stroke volume) is ejected through the mitral valve 6 into the aorta 12 and then to the body.
Referring to FIG. 2, the mitral valve 6 has two leaflets. The anterior leaflet 14 has a semicircular shape and attached to approximately two-fifths of the perimeter of the valve annulus 4. The free edge 15 of the anterior leaflet 14 is typically continuous, without indentations. The posterior leaflet 16 of the mitral valve 6 is attached to approximately three-fifths of the perimeter of the valve annulus 4. Typically, the posterior leaflet 16 has three segments: the anterior scallop 18, the middle scallop 20, and the posterior scallop 22. The anterior scallop 18 is divided from the middle scallop 20 by a first indentation 24, and the middle scallop 20 is divided from the posterior scallop 22 by a second indentation 26. The indentations 24, 26 aid in posterior leaflet 16 opening during diastole. The free edge 24 of the posterior leaflet 16 contacts the free edge 15 of the anterior leaflet 14 when the mitral valve 6 is closed. The height of the posterior leaflet 16 is typically less than the height of the anterior leaflet 14; however, both leaflets 14, 16 typically have generally similar surface areas.
The use of the same reference symbols in different figures indicates similar or identical items.